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How to request openings like a pro...

(Bascule bridge)

Last winter, our friends Susan and Scott came down to Florida to escape the Lake Erie winter and do a little sailing. I enjoy having other sailors aboard. It provides an opportunity to learn new techniques and to clean up those bad habits that accumulate after I have been doing things "my way" for too long.

After a welcome-aboard coffee we went through our pre-sail checkout: location of safety gear, arrangement of running rigging, and so forth. We ended up at the nav station, where I spread out a chart depicting our local sailing waters. We had planned a simple offshore sail south of Cape Canaveral. I traced our course with my finger and explained, "We motor east, pass under the 401 drawbridge, get sail up just past this jetty . . . "

"Whoa!" said Scott, "I've never dealt with a drawbridge." I was surprised. Drawbridge openings have been part of my sailing experience from the beginning. I realize now that many experienced sailors have never "opened" a bridge, and a few have confessed to being a bit intimidated at the prospect of doing so.

Planning for bridges

Bridge planning begins with a study of the nautical charts. Bridges identified as "bascule," "swing," or "lift," are all types of opening bridges. The bascule is the type most often imagined when hearing the term "drawbridge." This design consists of one or more spans hinged at one end while the other end rises in a vertical arc when opening. A swing bridge pivots at the center as the opening spans move in a horizontal arc, creating two parallel channels. Lift bridges are the most complex and least common of opening bridges. The spans rise vertically in the same plane supported at each end by tall columns. This type of bridge also has the disadvantage of being height restrictive even when fully open.

The charts will also denote horizontal and vertical clearances beneath the bridge. Horizontal clearance represents the width of the navigable channel at its most restrictive point. Vertical clearance is measured from mean high water to the bottom of the bridge at the center of the channel with the bridge in its closed position. This value, compared to your mast height, determines the need for an opening.

Schedules and curfews

Some bridge operators will open on demand any time, day or night, while others will open only in accordance with an established schedule. Bridge operators may also observe curfews that prohibit opening during periods of heaviest motor traffic. A typical schedule for a bridge on a busy roadway might specify openings on the hour, with no openings between the hours of 6 and 8 a.m. Conversely, some railway bridges remain in the open position until a train approaches. Restrictive schedules and curfews are becoming more common and may represent anything from an annoyance to a hazard if not planned for.

Standards for bridge operations, including schedules, are established in the Code of Federal Regulations, 33 CFR 117. This document may be obtained through the U.S. Government Printing Office or viewed online at:

A much more practical source of bridge information is the Coast Pilot. These handy supplements to the nautical charts are published periodically by the National Oceanic and Atmospheric Administration (NOAA) and contain a wealth of information indispensable to the coastal sailor. Coast Pilots may be purchased from NOAA Chart Agents, ordered online, or downloaded free of charge on the NOAA website: . 

(Swing bridge)

Temporary changes to bridge schedules are sometimes necessary to accommodate repairs or scheduled maintenance. These are published in Local Notices to Mariners. Local notices are no longer distributed in paper form but may be viewed or downloaded from the Coast Guard's nav center website: . Coast Guard stations also transmit "Securité" broadcasts periodically on VHF Channel 16, detailing hazards to navigation, including bridge irregularities, in their areas.

There are many locally focused, yet unofficial means of determining bridge schedules. The last, but perhaps most certain, source of schedule and curfew information is the bridge itself. Signs listing schedules, the name of the bridge, and VHF radio channels monitored are commonly posted on bridges.

"I realize now that many experienced sailors have never "opened" a bridge, and a few have confessed to being a bit intimidated at the prospect of doing so."

Thinking ahead

When approaching a bridge, the prudent skipper will assess the situation and prepare the vessel and crew for a safe passage. Here are five steps I use: 

1. Note the time and determine if you will be in position and properly prepared to pass in compliance with the schedule. If not, prepare to stand off for the next opening.

2. Evaluate the course and width of the channel as it approaches, passes under, and departs the bridge. Conventional channel markers or buoys typically mark the approach and departure courses. The bridge channel may be defined by similar markers or by the presence of large protective fenders. At night, the lateral limits of the bridge channel are marked with red lights. The overhead spans are marked with one or more steady red lights when closed. These lights switch to steady green when the spans reach the fully open position.

3. Identify other vessels approaching from the same and opposite directions. Consider the navigation right of way rules. Determine if the bridge channel is wide enough to allow passing or if it might be smarter to stand off until other vessels are clear. If in doubt of another mariner's intention, hail the vessel on VHF Channel 16 and ask.

4. Estimate the force and direction of wind and current. Remember that both may be altered and intensified by the bridge structure. Weigh the potential effects of these forces on other boats as well as your own. It is best if auxiliary sailboats navigate bridges under power. Motoring allows for more immediate response to the often-changing conditions under a bridge. If you choose to proceed under sail, your awareness of wind and current beneath the bridge becomes even more critical. Be certain of your abilities and those of your crew and boat.

5. Mentally formulate your plan and share it with your crew. Assign and complete any tasks necessary to prepare the boat for the bridge passage.

Hailing the bridge tender

Mariners approaching an opening bridge are required to signal their intentions, and the bridge operator is required to respond (33 CFR 117). The preferred method is by radiotelephone. Bridge tenders routinely monitor VHF Channels 16 and 13, except in Florida where they monitor channels 16 and 9. Other conventions apply in other regions. Learn what they are for the area you're cruising.

(Lift bridge)

Hail the bridge tender as you would another vessel. State the name of the bridge, your boat's name, and the VHF channel you are using. If you hailed on Channel 16, expect to be directed to another channel in the initial response. After communication is established, state your request in simple terms. The bridge tender will respond that an opening is available or will specify any delay that you should expect. He or she will also include any other information or questions deemed important. Likewise, if you have questions or concerns about the operation, ask. In my experience, bridge tenders are a professional and courteous lot, always ready to assist the transiting mariner. Continue to monitor the appropriate channel until your passage is complete and you are clear of the bridge.

Sailors without radios need not despair; 33 CFR 117 provides for the use of audible and visual signals. To request an opening audibly, sound one long and one short blast as you approach the bridge. If an immediate opening is possible the operator will respond with the same signal. Five short blasts indicate a delay, to be followed by one long and one short when the opening is available.

A white flag, raised and lowered, is the proper visual signal to request a bridge opening. At night, raise and lower a single white, green, or amber light. A response of the same signal indicates an immediate opening. A red flag or horizontally swung red light signals a delay.

Passing under

The bridge tender will stop roadway traffic and sound one long blast to signal the beginning of the opening process. This is your cue to position your boat for passage. If you do not intend to stand off for other vessels, continue toward the bridge at a speed that provides good steerageway but does not produce a significant wake. Be sure that the spans are fully open before proceeding under the bridge.

The helmsman must be alert and ready to correct for the effects of wind, current, and the wakes of other vessels. Everyone on deck should be careful of swinging booms and flailing lines caused by turbulent wind conditions that are common beneath bridges.

When all vessels are clear, the bridge tender will sound five short blasts indicating the spans are about to close. If you are not clear of the bridge, immediately respond with five short blasts. When clear of the bridge and other vessel traffic, resume speed and configuration appropriate to conditions. Switch your radio back to Channel 16 after thanking the bridge tender for the opening.


It is true and a bit sad that opening bridges are going the way of the steam engine and sextant. Transportation departments are replacing them with elevated, fixed bridges that impose no delays on highway or water traffic and are far less expensive to maintain. There are, however, many bascule, swing, and lift bridges still spanning rivers, waterways, and harbor entrances. A prudent sailor should know how to navigate beneath them safely and confidently.